I remember he had a white, almost glass/crystal looking sword that could shoot an energy burst. The evil master had a similar sword, and when combined they became even more powerful (something which happened much more often than it ever did in He-Man).

Sounds like the Filmation series that was
made a couple of years before
The Master's of the Universe/He-Man
Filmation's,

Blackstar (83)

Astronaut John Blackstar was pulled through a black hole into another universe and crash landed on the planet Sagar. He was found by a friendly group of native dwarf-like people (The Trobbits), and their friends Klone ( a shape-shifter), and Mara the sorcerous. John Blackstar joined their struggle to remain free from the grip of the tyrant, Overlord.
Blackstar's main advantage in the fight against Overlord was the StarSword. The The Star Sword was half the blade of an unstoppable sword that would allow it's owner to become invincible.
Overlord had the Power Sword,the other half of the sword, and he was determined to get Blackstar's half.
Warlock was Blackstar's flying dragon steed.